Refrigeration system and control valve therefor



March 27, 1956 T. E. NOAKES REFRIGERATION SYSTEM AND CONTROL VALVE THEREFOR Filed April 10, 1952 mwmZmOZOU {44v ATTORNEY United REFRIGERATION SYSTEM AND CONTROL VALVE THEREFGR Thomas E. Noakes, Detroit, Mich, assignor a) Detroit Controls Corporation, Detroit, Mich, a corporation of Michigan j 7 Application April 19, 1952, Serial No. 281,535

16 Claims. (Cl; 62-2} This invention relates to new and useful improvements in refrigeration systems and control valves therefor, and

v more particularly to a system and control valve for directing the flow of hot compressed refrigerant to the evaporator coils for the purpose of defrosting,

One of the objects of this invention is to provide a new and improved refrigeration system having an improved defrosting means therein.

Another object is to provide a new and improved refrigerant evaporator defrosting control arrangement.

Another object is to provide a refrigeration system having a newand improved control valve for directing the how of compressed refrigerant to a refrigerant evaporator for defrosting the same.

Another object is to provide a new and improved automatically operated control valve for a refrigeration defrosting arrangement.

Another object is to provide a new and improved automatically operated fluid flow directing valve.

Other objects will become apparent from time to time in the specification and claims as hereinafter related,

This invention comprises the new and improved construction and combination of parts which make up this system and also the new and improved control valve there is a compressor 1, condenser 2, capillary tube or other suitable expansion device 3, and an evaporator 4. The compressor 1 is connected by a conduit to the inlet side of the condenser 2, the outlet 6 of which is connected to one inlet 2t)? of a flow controlling valve 208. The valve 208 has a normally open outlet 2:39 connected to the capillary tube 3 and has a normally closed by-pass outlet are connected to a by-pass conduit 247 which connects to a T-connector 245 at the inlet to the evaporator 4. The outlet end of the evaporator. 4is connected by, a conduit 219 to a second inlet 22% in the valve 208 which also has an outlet 235 connected by a conduit 236 to the inlet of the compressor 1. The valve 208 comprises a casing generally designated 231 having a tubular portion 212 and an enlarged end portion 213. The casing 211 is provided with an internal longitudinal bore 215 which extends from the inlet end 207 in the tubular portion 212 to the enlarged end portion 213 and opens into a recess 214- formed in said enlarged end portion. The tubular portion 212 is provided with laterally'extending projections or bosses 216 and 217, respectively, for the outlet connections 209 and 216. There are also provided pas- Patent 2 sages 218 and 221 connecting the outlets 269 and 210, respectively, with the bore 215 which connects them to the inlet 207. The longitudinal bore 215 has a reduced portion in which there is positioned a valve seat member 222 between the passages 218 and 221 and which provides a valve port which is normally closed by a valve member 223. The valve-member 223 is carried by a valve stem 22% which extends through the bore 215 into the end recess 214. The bore 215 has a portion 225 of reduced diameter which guides the valve stem 224 in sealing relation with a sealing ring 226 carried by said stem to prevent flow around said stem. The enlarged end portion 213 of the valve casing has a laterally extending boss 227 through which extends the inlet passage 220 to the recess 214. The recess 214 is provided with a valve seat 228 through which opens an enlarged portion 229 of the longitudinal bore 215. The valve seat 228 is provided with a notch 248 which provides a restricted opening when the valve member 231 is closed against the valve seat 228. The enlarged end portion 213 of the casing has another laterally extending boss 230 through which extends the outlet opening 235 which opens into the enlarged bore portion 229. The upper end of the valve stem 224 has a valve member-231 secured thereon and I normally open position and holds the valve member 223 in a normally closed position. The wall of the recess 214 functions as a guide for a thrust member 237 which has an annular knife-edge projecting portion 238 cu gaging the snap disc 232 and operable upon movement to snap said disc to an overcenter position for quick closing of the valve member 231 and opening of valve member 223. The casing end portion 213 is provided with a peripheral flange and rim portion 239 providing an internal annular shoulder 240; There is provided a corrugated diaphragm 241 which extends across and closes the end ofthe recess 214 and which has a peripheral rim portion 242 which seats on the annular shoulder 240. A dished cover member 243 is positioned in overlying relation to the diaphragm 241 to form a power element chamber therewith and has a peripheral rim 244 seating against the rim 242 and the annular shoulder 240 to secure the diaphragm 241 in position. The flange 239 and rims 242 and 244 are joined as by a' welded, soldered, or

brazed connection indicated as 249. The cover member 243 has a central tubular projection 250 providing an inlet connection for a small bore tubing 251 which is connected therein as by soldering and which carries on its other end a feeier bulb member 252. The bulb member 252, tubing 251, and the power element chamber 253, which is enclosed between the diaphragm 241 and cover member 243, are filled with a suitable temperature responsive, fluid which is adapted to respond to the formation of ice on the evaporator coils 4. The thermostatic liquid used is preferably one which expands upon freezing, such as water. If water is used as the responsive fiuid, the freezing point is varied by mixing therewith a freezing point depressant such as alcohol, glycol, etc.

Operation In the operation of this system, the bulb element 252 of the valve 208 is positioned adjacent the evaporator coils 4 so that upon occurrence of a predeterminedthickness of ice on said coils the valve will be actuated automatically to defrost the evaporator coils. in normal operation, the primary flow of compressed refrigerantthrough the valve 208 is through inlet 207, passages 215 and 218, and outlet 216to the'capillary tube 3 and from there through the evaporator and back to the compressor.

. When the bulb element 252 responds to the formation of ice on the evaporator coils, there occurs an expansion in the power element chamber 253 which will move the diaphragm 241 and thrust member 237 sufficiently downward to cause the snap disc 232 to move the valve member 231 to closed position against the valve seat 228 and to move the valve member 223 to open position away from its valve seat 222. With the valve 208 in this actuated position, the restriction provided by the capillary tube 3 will cause the primary flow of compressed refrigerant to go through the by-pass conduit 247 so that hot compressed refrigerant is supplied to the evaporator coils 4 for defrosting. When the valve member 231 is closed against its valve seat 223, the notched opening 248 provides a restriction to prevent the flow of liquifiedrefrigerant back into the compressor 1. When the ice has melted sufliciently from the evaporator coils 4 so that the bulb element 252 indicates this condition, the diaphragm 241 will again move upward and allow the snap disc 232 to snap back to its original position closing the valve member 223 and opening the valve member 231 for normal system operation.

' Although there has been shown and described in this specification a preferred embodiment of this invention, it is to be understood that other embodiments of the invention are possible and the scope of the invention is intended to be limited only by the appended claims.

Having thus described the invention, what is claimed and desired to be secured by Letters Patent of the United States is:

' 1. In a refrigeration system, a compressor, a condenser, an expansion device, and an evaporator, connected in a series conduit circuit for compression, condensation, flow, and expansion of a volatile refrigerant, said circuit including a continually open conduit directly connecting the outlet of said compressor to said condenser so that all of the refrigerant discharged by said compressor is at all times supplied directly to said condenser, a by-pass conduit connected to pass compressed refrigerant around said expansion device; valve means comprising a first valve connected to and controlling flow through said bypass conduit, said first valve having a normally closed position directing flow of refrigerant to said expansion device, a second valve normally open and connected in and controlling flow through the return connection from said evaporator to said compressor, mechanical means operatively interconnecting said valves for conjoint operation so that opening of said first valve will effect closure of said second valve, means to actuate said valve means to said position in which said first valve is opened and said second valve is closed to direct refrigerant flow in'a circuit by-passing said expansion device, and said valve means including means providing a restriction in the return connection from said evaporator to said compressor when in said actuated position.

2. In a refrigeration system, a compressor, a condenser, an expansion device, and an evaporator, connected in a series circuit, said circuit including a continually open, conduit directly connecting the outlet of said compressor to said condenser so that all of the refrigerant discharged by said compressor is at all supplied directly to said condenser, a lay-pass conduit connected to said evaporator in parallel relation to said expansion device, a valve casing having a plurality of inlets and outlets, the first of said inlets being connected to said condenser, the second of said inlets being connected to the outlet end of said evaporator, the first of said outlets being connected to said expansion device, the second of said outlets being connected to the inlet side of said compressor, the third of said outlets being connected to said by-pass conduit, a continually open passageway interconnecting said first inlet and outlet, a normally closed passageway interconnecting said first inlet and third outlet, means forming a valve seat in said last-named passageway, a valve member normally closing said valve seat, a normally open passageway interconnecting said second inlet and outlet, means forming a valve seat in said last-named passageway, a valve member carried in normally open relation to said lastnamed valve seat, means interconnecting said valve members for conjoint operation, said last-named valve seat and valve member providing a restricted opening in said last-named passageway when in closed position, and means to actuate said valve members to closed and open positions, respectively, to direct the principal flow of refrigerant to said evaporator through said by-pass conduit.

3. A system as defined in claim 2 wherein the valve actuating means is a thermostatic means responsive to the formation of a predetermined amount of ice on the evaporator.

4. In a refrigeration system, a compressor, a condenser, an expansion device, and an evaporator, connected in a series circuit, said circuit including a continually open conduit directly connecting the outlet of said compressor to said condenser so that all of the refrigerant discharged by said compressor is at all times supplied directly to said condenser, a by-pass conduit connected to said evaporator in parallel'relation to said expansion device, a valve casing having a plurality of inlets and outlets, the first of said inlets being connected to said condenser, the second of said inlets being connected to the outlet end of said evaporator, the first of said outlets being connected to said expansion device, the second of said outlets being connected to the inlet side of said compressor, the third of said outlets being connected to said by-pass conduit, a continually open passageway interconnecting said first inlet and outlet, a normally closed passageway interconnecting said first inlet and third outlet, means forming a valve seat in said last-named passageway, a valve member normally closing said valve seat, a normally open passageway interconnecting said second inlet and outlet, means forming a valve seat in said lastnamed passageway, a valve member carried in normally open relation to said last-named valve seat, means interconnecting said valve members for conjoint operation, said last-named valve seat and valve member providing a restricted opening in said last-named passageway when in closed position, means to actuate said valve members to closed and open positions, respectively, to direct the principal flow of refri erant to said evaporator through said by-pass conduit, and said actuating means including snap acting means for snap movement of said valve members to and from actuated positions.

5. In a refrigeration system, a compressor, a condenser, an expansion device, and an evaporator, connected in a series circuit, a bypass conduit connected to said evaporator in parallel relation to said expansion device, a valve casing having a plurality of inlets and outlets, the first of said inlets being connected to said condenser, the second of said inlets being connected to the outlet end of said evaporator, the first of said outlets being connected to said expansion device, the second of said outlets being connected to the inlet of said compressor, the third of said outlets being connected to said by-pass conduit, a continually open passageway interconnecting said first inlet and outlet, a normally closed passageway interconnecting said first inlet and third outlet, means forming a valve seat in said last-named passageway, a valve member normally closing said valve seat, the end of said casing adjacent said second inlet and outlet having a recess therein and a peripheral rim, means including said recess providing a normally open passageway between said second inlet and outlet, means forming a valve seat in said last-named passageway, a valve member in said recess engageable with said last-named valve seat, a notched passageway providing a restricted opening between said last-named valve member and valve seat when in closed position, a snap disc positioned in said recess and carrying said last-named valve member in a normally open position, a diaphragm closing said recess, a cover member sealing said diaphragm against said casing rim, said cover member and diaphragm providing a power element chamber, a power element bulb and capillary tube therefor connected through said cover member into said power element chamber, said power element chamber, bulb, and capillary tube being charged with a thermostatic fluid, a thrust member positioned in said recess for transmission of movement from said diaphragm to said snap disc, a valve stem reciprocally guided in said casing and interconnecting said valve members for conjoint movement thereof, said bulb element being positioned to respond to the formation of ice on said evaporator, and said thermostatic fluid expanding upon response to ice formation to actuate said valve members to open the first and close the second-named valve member with a snap movement to direct refrigerant flow through said by-pass conduit. Y

6. A flow control valve for use in a refrigeration system having a compressor, a condenser, an expansion device, an evaporator, a continually open conduit directly connecting the outlet of said compressor to said condenser so that all of the refrigerant discharged by said compressor is at all times supplied directly to said condenser, and a by-pass conduit; said valve comprising a valve casing having a plurality of inlets and outlets, the first of said inlets being connected to said condenser, .the second of said inlets being connected to the outlet end of said evaporator, the first of said outlets being connected to said expansion device, the second of said outlets being connected to the inlet side of said compressor, the third of said outlets being connected to said by-pass conduit, a continually open passageway interconnecting said first inlet and outlet, a normally closed passageway inter-' last-named valve seat and valve member providing a restricted opening in said last-named passageway when in closed position, and means to actuate said valvemem- 1 bers to closed and open positions, respectively, to direct the principal fiow of refrigerant to said evaporator through said by-pass conduit.

7. A valve as defined in claim 6 wherein the valve actuating means is a thermostatic means responsive to the formation of a predetermined amount of ice on the evaporator.

8. A flow control valve for use in a refrigeration system having a compressor, a condenser, an expansion device, an evaporator, a continually open conduit directly connecting the outlet of said compressor to said condenser so that all of the refrigerant discharged by said compressor is at all times supplied directly to said condenser, and a by-pass conduit; said valve comprising a valve casing having a plurality of inlets and outlets, the first of said inlets being connected to said condenser, the second of said inlets being connected to the outlet end of said evaporator, the first of said outlets being connected to said expansion device, the second of said outlets being connected to the inlet side of said compressor, the third of said outlets being connected to said by-pass conduit, a continually open passageway interconnecting said first inlet and outlet, a normally closed passageway interto closed and open positions, respectively, to direct the principal flow of refrigerant to said evaporator through said by-pass conduit, and said actuating means including snap acting means for snap movement of said valve members to and from actuated positions.

9. A flow control valve for use in a refrigeration system having a compressor, a condenser, an expansion device, an evaporator, and a by-pass conduit; said valve comprising a valve casing having a plurality of inlets and outlets, the first of said inlets being connected to said condenser, the second of said inlets being connected to the outlet end of said evaporator, the first of said outlets being connected to said expansion device, the second of said outlets being connected to the inlet of said compressor, the third of said outlets being connected rim, means including said recess providing a normally open passageway between said second inlet and outlet, means forming a valve seat in said last-named passageway, a valve member in said recess engageable with said last-named valve seat, a notched passageway providing a restricted opening between said last-named valve mem- I her and valve seat when in closed position, a snap disc positioned in said recess and carrying said last-named valve member in a normally open position, a diaphragm closing said recess, a cover member sealing said diaphragm against said casing rim, said cover member and diaphragm providing a power element chamber, a power I element bulb and capillary tube therefor connected through said cover member into said power element chamber, said power element chamber, bulb, and capillaryv tube being charged with a thermostatic fluid, a thrust member positioned in said recess for transmission of movement from said diaphragm to said snap disc, a valve stem reciprocally guided in said casing and interconnecting said valve members for conjoint movement thereof, said bulb element being positioned to respond to the formation of ice on said evaporator, and said thermostatic fluid expanding upon response to ice formation to actuate said valve members to open the first and close the secondnarned valve member with a snap movement to direct refrigerant tlow through said by-pass conduit.

10. A flow controlling valve comprising a valve casing having a longitudinally extending tubular portion and an enlarged end portion, said enlarged end portion having arecess therein, said tubular portion having a passage opening into said recess, one end of said passage providing a first inlet, the other end of said passage having a portion forming a valve port and seat, said enlarged end having bosses formed thereon, one of said "bosses having an inlet opening into said recess,-the other of said bosses having an outlet opening from said passage below said valve seat, said tubular portion having laterally extending bosses with outlets formed therein opening from said passage, a valve seat member positioned in said passage between said last-named outlets, a first valve member normally closing said last-named valve seat to close oil flow therethrough, a second valve member in said recess in normally open relation to said first-named valve seat, a valve stem interconnecting said valve mem bers for conjoint movement, said passage having a guide portion of reduced diameter between said last-named outlets and said second-named inlet for guiding movement of said valve stem, sealing means in said guide portionto prevent leakage around said valve stem, a snap disc in said recess, means securing said valve stem and second valve member to said snap disc for movement thereby,

a diaphragm closing said recess, a thrust member positioned to transmit movement from said diaphragm to said snap member, a cover member sealed in said recess against the periphery of said diaphragm and defining therewith a power element chamber, a bulb element and capillary tube connected in said cover member to said power element chamber, and said peWer element chwiber, bulb element, and capillary tube having a thermostatic fluid therein.

References Cited in the file of this patent UNITED STATES PATENTS McCloy June 13, 1944 

